Core C is the Resources Core. All three Projectswill rely extensively on histological analysis of mouse hearts. Centralization of equipment, technical expertise and reagents will facilitate these activities and minimize the associated costs. Specific activities of Core C include (1) assistance with routine paraffin embedding and sectioning, (2) assistance with routine cryopreservation and sectioning, (3) assistance with standard histochemical staining (i.e., Hematoxylin and Eosin, Alcian blue, Masson's trichrome, Sirius red and fast green, von Kossa, etc), (4) assistance with in situ hybridizations, and (5) assistance with routine immune histology analyses (i.e., TUNEL, BrdU, sarcomeric actin, myosin heavy chain, etc). Given the heavy utilization of histologic analyses by all three projects, Core C is essential for the successful completion of the proposed experiments.